Binary and Multi-Level Cell (MLC) NAND Flash Memory are forms of non-volatile memory (NVM) that are capable of high data storage densities and high performance, however, a power failure due to hot removal, brownout, blackout or the like can cause data corruption or loss due to the nature of the way in which data is written to this type of memory. Typically a “page” or group of bits at a time is written to the NVM. If a power failure occurs during a write cycle/program operation, something less than all of the bits of the page may be programmed successfully in the NVM. When the page containing unsuccessfully programmed bits is read back, some bits will have the new value, some will have the old value and, as a result, the page will be corrupted. In some prior approaches, complex data structures and multiple copies of host data are kept on the NVM device to ensure graceful recovery under most circumstances. This approach, unfortunately, reduces performance and data storage densities. An NVM program cycle using Flash-type memory, for example, typically takes on the order of 0.5-10 mSec, depending upon the type of memory.
This problem can be addressed through the use of a backup or secondary power source arranged to directly power the NVM such as a battery or very large-valued capacitor (on the order of 1000's of uF), but these solutions are often costly or require too much space. An improved solution would be desirable.